Laws, Theories and the nature of science

After reading a few quips on 'settled science' and 'scientific consensus' I decided a separate thread was warranted. Plus this has been a pet peeve of mine for a while since the word 'Theory' is thrown around even by those that should know better...

So a few basics;

Scientific Law - IS A DESCRIPTION

Scientific Theory - IS AN EXPLANATION

There is no hierarchy. Theories do not graduate to laws and laws are not superior to theories. If all we had were LAWS then we would have a very well DESCRIBED universe but nothing would be EXPLAINED. A hypothesis is essentially an untested theory.

NOTHING in science is PROVEN. I actually had this discussion with a co-worker today... here's a helpful analogy.

I have two dice. You don't know how many sides the dice have... you only get the sum of the roll. Every roll is a test.

2,7,8,3,10,12,7,5,7,4,3,8,2...... ∞

At some point it's obvious that these are two 6 sided dice but you can NEVER prove it. A single # rolled >12 would DISPROVE that theory but the theory can NEVER be proven.... it's effectively SETTLED; Unless you want to be uselessly pedantic in which case NOTHING is 'settled'. Some people become convinced when the probability of it NOT being two 6-sided dice is so low that it becomes absurd to accept any other conclusion. Others will hold out indefinitely because the existence of 6-sided dice threatens their worldview. Politicians courting those people will claim all the numbers aren't yet in and they aren't mathematicians.

None of which changes the fact that;
- the odds are very very high that you do indeed have two 6-sided dice
- you can never say with 100% certainty that the next roll won't be >12 only 99.99999999999999.....% certainty

But! but! but! It's settled! It's proven! It's not up for debate! We need to have a law that punishes anyone who dares to suggest you have anything other than 2 6-sided dice! This is the WORLD we're talking about, after all! If you're not with us and agree with us 100%, you're against us!

(You could have a 4-sided die and an 8-sided die as well, and that would still fit your set 99.9999999999999...% of the time. You never said they had to be two equal dies! But the people who think the "settled science" of 6-sided dice only see 6-sided dice, and are simply not open to a combination of a 4-side die and 8-side die.)

There's a reason that 25% of some science classes cover "what is science?" - thanks for putting this out there, as it's not understood by a lot of people.

(You could have a 4-sided die and an 8-sided die as well, and that would still fit your set 99.9999999999999...% of the time. You never said they had to be two equal dies! But the people who think the "settled science" of 6-sided dice only see 6-sided dice, and are simply not open to a combination of a 4-side die and 8-side die.)

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That theory would fit... but the statistical distribution would eventually weigh against it. '7s' would be too common for that theory to explain but that thought process is 100% right... other alternatives that 'fit' need to be considered. It's equally critical for improbable alternatives to be weeded out even though they cannot be completely ruled out.

That said... if we continually returned to the statistically improbable there would be little progress and there would be much chaos. You have to work within the confines of a structured paradigm to build knowledge. Progress REQUIRES acceptance of the most probable truth. There's a huge difference between having a questioning attitude and questioning everything.

It's not impossible that drunk driving and accidents are not causally related... but that likely hood is so improbable that it would be absurd to not pass laws against drunk driving.

It's not impossible that vaccines don't actually work... but that likely hood is so improbable that we've mandated vaccines for school children.

It's not impossible that the effects of CO2 won't be disastrous... but that likely hood is so improbable that it's morally prudent that we act to dramatically reduce our fossil fuel use.

The fact that nothing in science is ever PROVEN... does not remove our responsibility to act as though it is...

I'm gonna quibble, though it's more of a semantic sort of quibble. . .

"Proven" is a synonym for "tested". Proof is what science is all about. Science is the systematic accumulation of proven (i.e. tested) knowledge about how our universe works. If it can't be tested, it's not science.

I think what you meant is that no test, or proof, is ever absolute. And that's OK.

I'm merely 38 and can remember a time where the scientific community was absolutely sure black holes were supremely rare, then one day they changed their tune and super-massive black holes were at the center of every single galaxy. No trumpets, no white paper explaining why something that was immutable fact yesterday is now patently false.

Scientists are my favorite folks, but they're naturally blinded by their current list of "facts". Super smart, but in most cases not smart enough to grasp the how much they don't or can't understand.

I'm merely 38 and can remember a time where the scientific community was absolutely sure black holes were supremely rare, then one day they changed their tune and super-massive black holes were at the center of every single galaxy. No trumpets, no white paper explaining why something that was immutable fact yesterday is now patently false.

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No serious astrophysicist was "absolutely sure" about anything about black holes until a few years ago. Even now, it is possible that black holes aren't the correct theory, although it would require some unknown quantum mechanical force to cause general relativity to fail as an explanation of gravity, which is certainly not the most likely outcome. As recently as 1997 there was still a raging debate about fundamental questions like does quantum mechanics still apply inside a black hole. Throughout the 50s and 60s there were still plenty of folks who believed they were a mathematical curiousity, not real objects -- but virtually no one who was asserting that it was an "immutable fact" that black holes were rare, or even that they actually existed. Even today, there is no absolute proof of the existance of black holes, although Haystack is probably going to provide fairly definitive proof of Sagittarius A being a supermassive black hole in the next few years.

The evolution of our understanding of black holes (of which there are many different types, btw) is a pretty classic demonstration of how science actually works. It went from a weird mathematical edge case resulting from Einsteins numbers, to "hey this could really happen" to "man, this actually explains quite a lot."

The way I think about science is that it builds models of the universe based on observations, some of which are very carefully contrived, i.e. experiments, that are able to predict what will happen in some as yet unobserved case. Practically, it allows us to do engineering, e.g. build semiconductors, airplanes, cancer treatments, etc. by design rather than by cut and try.

The key point is the word "model", as distinct from words like "truth" or "reality". IMHO science isn't about discovering some single underlying truth that explains everything, it's about creating better and better models. An example is the transition from Galileo to Newton to Einstein WRT gravity. None of their physics was shown to be wrong, just incomplete; each model was better than the last and allowed more accurate predictions to be made. The transition from Aristotle to Galileo was an example of a transition from non-science "truth" based on reason to a scientific model based on observation. Aristotle's physics was pretty useless for engineering, but Galileo's was much better. To me, this is the fundamental difference between faith and science. Faith doesn't change since it claims absolute truth based on some infallible source. For faith, change means that the source was wrong which is pretty catastrophic. Science is just trying to build better and better models, so a change is of no more consequence than adjusting your side view mirror.

As others have alluded to, there's also no reason at all to think that our current theories about how the universe works are "correct" in any absolute philosophical sense. There may in fact be other very different models that explain the observations and allow predictions just as well as our current ones, we just haven't thought of them. If they were discovered though, they would be just as valid until some observation showed a case that worked for one but not the other.

You could have a 4-sided die and an 8-sided die as well, and that would still fit your set 99.9999999999999...% of the time. You never said they had to be two equal dies!

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This economist says you're both assuming that the faces of the dice are numbered 1 through x. If the hypothetical example states that you don't know how many sides the dice have, how would you know that the sides were numbered sequentially starting at the number 1?

I'm gonna quibble, though it's more of a semantic sort of quibble. . .

"Proven" is a synonym for "tested". Proof is what science is all about. Science is the systematic accumulation of proven (i.e. tested) knowledge about how our universe works. If it can't be tested, it's not science.

I think what you meant is that no test, or proof, is ever absolute. And that's OK.

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The issue is that any useful scientific theory has a quantitative basis, which means an inherent reliance upon mathematics. In mathematics, proof is always absolute. Since there is no way to observe every possible physical case, the mathematical definition of proof can never be satisfied.

Your statement that "if it can't be tested, it's not science" is correct. I give my intro lectures for physics and astronomy for the fall semester next week, and these points (along with most of the highlights of this discussion) will be emphasized.

Interesting discussion. But how do I translate it into action? Either to (a) convince me that I'm wasting my time thinking that there is enough evidence and theory to support acting as if AGW is a concern to be taken so seriously that it's wise to pursue significant policy changes (e.g., carbon pricing); or (b) to help me convince others who currently disagree that it's worth pursuing policy changes.

Having watched a number of the AGW debates here and on teslamotors.com, and even having participated to a small extent, I have come away thinking that not a single person's mind has been changed. I can't say I'm surprised by that.

An astronomer, a physicist and a mathematician are on a train in Scotland.

The astronomer sees a black sheep standing on a hill, and proclaims: "All sheep in Scotland are black!"

The physicists instead says: "At least one sheep in Scotland is black!"

The mathematician corrects them both: "At least one half of one sheep in Scotland is black!"

The problem is that climate science deniers can't tell the difference between these.

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In a sense all 3 are correct -- the astronomer only knows of 1 sheep and his data set is consistent, the physicist clarifies that we only know about the 1 sheep instance, and the mathematician clarifies further that we only have partial data on that one instance.

In another sense they could still all be wrong -- it might be a different colored sheep standing in the shadow of a tree, appearing black for the moment.

Anyone who is interested in this stuff should read Kuhn's "Structure of Scientific Revolutions". It is probably the most important insight into the history of science published in the last century, and it is brief, concise, and readable.

Bottom line of Kuhn's view: A system of scientific beliefs is built upon a group of demonstrated "knowns". When one of the "knowns" is proven flawed, there is a period of shock and horror, then a new set of "knowns are accepted and a new system of scientific beliefs is built upon that. This is the classic paradigm shift. Think the evolution from Aristotle to Copernicus, or Newton to Einstein. I may be getting my words wrong... I read it a few decades ago, but this is the gist.

Now, the fact that a paradigm may eventually be blown up, does NOT mean it is not largely valid, and doesn't mean every bit of the system of scientific beliefs is invalidated. The paradigm change usually just opens the door for more precision and more advancements in knowledge and thought. Newtonian physics is still very useful and mostly valid... unless you are a nuclear physicist, in which case you need relativity and whatnot. {I'm sure some scientist is going to slice and dice my layman's interpretation, but hey, I DID sleep in a Holiday Inn Express}

The fact that science "evolves", does not invalidate scientific method. Science naysayers better be careful, lest they stumble off the edge of the flat earth.

One post alluded to the principle of superposition. In science the new theory that replaces the old must also accurately predict those case where the prior theory worked or, put another way, must reduce to the prior theory. The best example I know is that when all velocities are significantly below the speed of light then relativity reduces to Newtonian mechanics. Also alluded to is something that I think should be pointed out more often and that is that mathematics is not a science. Mathematics is formalized logic and as such is a tool of science. Nothing is measured in mathematics. In mathematics you have a proof. In science you have a widely accepted theory.

My problem with climate change deniers is that they use the nature of science against it. You can always sow doubt. Gravity waves have never been detected. Do we throw out general relativity? If we do, then many things that depend on the theory for accurate calculations get thrown out with it and science actually goes backwards. It is easy to sow doubt. It is much harder to generate a superior theory. As shown in "Merchants of Doubt," this attack methodology started with tobacco. Sadly, it has been very effective. The best science gets torn down and replaced by nothing other than a wish for things to be different than they are. I haven't seen one denier explain away the Mauna Kea CO2 data other than to say that the scientists are lying and faking the data. This attitude is just plain sad.

Interesting discussion. But how do I translate it into action? Either to (a) convince me that I'm wasting my time thinking that there is enough evidence and theory to support acting as if AGW is a concern to be taken so seriously that it's wise to pursue significant policy changes (e.g., carbon pricing); or (b) to help me convince others who currently disagree that it's worth pursuing policy changes.

Having watched a number of the AGW debates here and on teslamotors.com, and even having participated to a small extent, I have come away thinking that not a single person's mind has been changed. I can't say I'm surprised by that.

Thanks,
Alan

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While I don't necessarily want this to devolve into another AGW debate, I really feel what Alan is saying here. For me, it comes down to a matter of throwing away everything controversial and seeing what's left. Measured CO2 rates are rising. At a certain concentration, CO2 becomes fatal to humans. Clearly at some point, rising CO2 concentrations become a problem, and it might be long before they are so high that people start dying just from breathing it in at too high a concentration. Of this, it should be possible to convince pretty much everyone. It's just a question of when it becomes a problem, and how big of a problem. And this is a critical concern, because we have only 1 atmosphere and only 1 currently livable planet within our reach (though Elon would like to increase that to 2 someday, but that's a long ways off). This far everything seems pretty much undeniable.

Who or what should we turn to to get an idea of when CO2 concentration changes become a problem, and how big of a problem it will be? And how long can we hold off to collect more data without unnecessarily increasing risk? This is where the real debate is. Hard as I try to come up with some other answer, the best answer I can come up with is the consensus findings of climate science. It's not a perfect answer. It just seems to be the best answer. It's a better answer than no answer. Isn't it? To those who disagree, where does this line of argument go wrong?

Interesting discussion. But how do I translate it into action? Either to (a) convince me that I'm wasting my time thinking that there is enough evidence and theory to support acting as if AGW is a concern to be taken so seriously that it's wise to pursue significant policy changes (e.g., carbon pricing); or (b) to help me convince others who currently disagree that it's worth pursuing policy changes.

Having watched a number of the AGW debates here and on teslamotors.com, and even having participated to a small extent, I have come away thinking that not a single person's mind has been changed. I can't say I'm surprised by that.

Thanks,
Alan

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The Climate Change / Global Warming Discussion thread is now more than two and a half years old. If you were to go through that thread from the beginning, you would find several TMC members that are still around on TMC that 2+ years ago challenged AGW, but who no longer post in that thread. You would also find that at least some of them have indeed altered their way of thinking about AGW.

Two+ years ago a few members also regularly posted misinformation in that thread. Since – and I don’t remember how long back – that doesn’t happen anymore. Why? I think that’s because they know that their misinformation will be shredded to scraps.

That thread also has ~171,147 views. Who knows how many who have used the arguments and the information posted in that thread to sway family, friends and acquaintances away from a misinformed viewpoint?

Interesting discussion. But how do I translate it into action? Either to (a) convince me that I'm wasting my time thinking that there is enough evidence and theory to support acting as if AGW is a concern to be taken so seriously that it's wise to pursue significant policy changes (e.g., carbon pricing); or (b) to help me convince others who currently disagree that it's worth pursuing policy changes.

Having watched a number of the AGW debates here and on teslamotors.com, and even having participated to a small extent, I have come away thinking that not a single person's mind has been changed. I can't say I'm surprised by that.

Thanks,
Alan

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Also:

How many of the TMC members that initially were questioning AGW do you think had previously encountered a veritable wall of other folks just shredding their misinformed viewpoint apart?

Those people questioning AGW were clearly smart, accomplished people, and clearly professionals in their respective line of work. Many had ordered or already owned one or perhaps even several Tesla vehicles (or owned other very, very expensive material objects/had lots of cash).

Admitting that you are wrong seems to be very, very hard for many people. And admitting that you are wrong about AGW seems to be especially difficult, since doing that arguably has the potential to shake your core values and beliefs on many different levels.

Therefore I don’t find it surprising at all that most of those that questioned AGW in the Climate Change / Global Warming Discussion thread hasn’t admitted that they’ve changed their views – if they have changed their views.

But if they were questioning AGW walking in to that thread, I’m convinced that at least some alterations to their viewpoint has taken place.

This is quite a fascinating topic, so please continue with the theory talk, but......

We now have tools that can split apart the molecules in the air and determine whether they came from cars, volcanoes, etc. by their chemistry composition. And the verdict is that most of them are CO2 from cars, so it's pretty hard coded in the science......I'm not sure how others can deny what's happening......

Anyone who is interested in this stuff should read Kuhn's "Structure of Scientific Revolutions". It is probably the most important insight into the history of science published in the last century, and it is brief, concise, and readable.